Substantive polymeric sunscreen composition

ABSTRACT

Sunscreening compositions for topical application to the skin comprising a cosmetic carrier material containing a polymeric reaction product of a para-dialkylamino benzoyl halide and a polyethylenimine. These sunscreening compositions, when applied to the skin of the user, form a film of the polymeric reaction product which is highly effective in protecting human skin from erythema-inducing ultraviolet radiation and is resistant to removal from the skin by water or perspiration.

United States Patent 11 Ciaudelli Feb. 4, 1975 [54] SUBSTANTIVEPOLYMERIC SUNSCREEN 3,642,572 2/1972 Endees et al. 260/78 A COMPOSITIONFOREIGN PATENTS OR APPLICATIONS [75] Inventor: Joseph P. Ciaudelli,Ramsey, NJ. 774,110 5/1957 Great Britain 424/78 7 A d 3] sslgnee a a Proucts Inc New York Primary Examiner-Albert T. Meyers I AssistantExaminerDale R. Ore Flledl J t 1972 Attorney, Agent, or Firm-Pennie &Edmonds [21] Appl. No.: 261,621

[57] ABSTRACT Sunscreening compositions for topical application to theskin comprising a cosmetic carrier material con- I o u s l l s s s s s sI o s s s I s s s s l u a. a a [58] Field of Search 424/59, 60, 260/78 Adialkylamino benzoyl halide and a polyethylenimine. These sunscreeningcompositions, when applied to the [56] References C'ted skin of theuser, form a film of the polymeric reaction UNITED STATES PATENTSproduct which is highly effective in protecting human 2,887,116 5/1959Wooding 424/78' X skin from erythema-inducing ultraviolet radiation and3,238,138 3/1966 Braunwarth et al. 424/60 i resi tant to removal fromthe skin by water or per- 3,529,055 9/1970 Skouttchi et alm. 424/59 xspiratim 3,600,350 8/1971. Kwolek 260/78 A 3,622,545 ll/l97l Foldi et al260/78 A 9 Claims, No Drawings 1 SUBSTANTIVE POLYMERIC SUN SCREENCOMPOSITION BACKGROUND OF THE INVENTION It is widely desirable in oursociety to secure tanning of the skin for purposes of appearance bysunbathing or other means. In order to enable or aid a person to subjectthemselves to tanning by such rays. several socalled sunscreeningcompositions have been made available to diminish or avoid thediscomfort and dangers of erythema which may be simultaneously produced.It is well known that the ultraviolet radiation produced by the sunbetween the wavelengths of about 280 millimicrons to about 320millimicrons are responsible for the distressing burning which issuffered by over-exposure. The ultraviolet radiation of longerwavelengths of up to about 420 millimicrons causes the aestheticallydesirable .tanning coloration of the skin.

It has been known by those skilled in the art that various compounds areuseful to absorb the undesirable ultraviolet radiation ranging from 280millimicrons to 320 millimicrons. Various aminobenzoic acid andsubstituted aminobenzoic acids are known to have the quality ofabsorbing the undesirable ultraviolet rays while transmitting those moredesirable sun tanning producing rays. Also, the derivatives ofparaaminobenzoic acid such as the dimethyl aminobenzoic acids have beenused in the past in sun tanning compositions. It is also known thatesters of P-aminobenzoic acid such as the methyL ethyl or propyl p-aminobenzoate as well as those esters formed from higher alkyl alcohols havevaluable sun-screening effects. Each of these compounds-while havingdesirable properties are not ideal for the purpose intended. They lackone or more of such desirable characteristics as solubility in cosmeticcarriers at low temperatures, nonstaining of fabrics, stabilityonstorage, stability on exposure to ultraviolet or visual radiation,resistance to oxidation to air. Moreover, compounds useful in absorbingerythema-causing rays are, when topically applied in the various knownforms, easily removed from the skin by salt or fresh water.

In as much as sunscreening compositions are generally used in hotweather and at beach and waterfacilities where people enjoy bathingactivities, such compositions which are removed by water have limitedeffectiveness. Even where artificially induced rays, such as bycommercially available sun lamps, are used the heat causes the user toperspire which erodes the sunscreening agents away.

Sunscreening formulations have been produced in attempts to overcome thesubstantive instability of the foregoing described sunscreeningmaterials. Ethylenically unsaturated ultraviolet absorbing compoundshave been polymerized in attempts to make a substantive sunscreeningmaterial. These materials have the disadvantages in that they maycontain small entrained quantities of harmfulmonomeric material or arepolymerized under conditions which reduce the sunscreening ability ofthe resultant product.

SUMMARY OF THE INVENTION It has now been found that sunscreeningformulations which are useful in absorbing the erythema-producing raysof the sun are formed from a polymeric reaction product produced frompara dialkyl aminobenzoyl halides and polyethylenimines. The polymericproduct LII thus formed can be encompassed into any of the variouscosmetic carrier materials known to be useful by the practitioner. Suchpolymeric products, when topically applied to the human skin, will forma film material which will resist removal from the skin by the action ofsalt or fresh water or perspiration.

Sunscreening formulations containing thepolyethylenimine-paradialkylaminobenzoyl halide reaction product arecapable of screening harmful ultraviolet radiation while permittingtransmission of the beneficial rays. In this manner the individual maysubject himself to sunlight to cause the aesthetically desirable tanningof the skin while alleviating the problems of sunburn or erythema whichis usually accompanied by discomfort and pain. The formulationscontaining the' polymeric product described herein forms when, topicallyapplied, a film material which adheres to the skin and resists removaltherefromeven when subjected to the action of fresh or saltwater orthrough perspiration of the individual. These compositions are,therefore, long lasting and need not be applied numerous times to insureproper protection.

DETAILED DESCRIPTION OF THE INVENTION The material which has herein beenfound to be an excellent sunscreening agent is produced from thereaction of polyethylenimine and a paradialkylaminobenzoyl halide. Theparadialkylaminobenzoyl halide may contain alkyl groups having from 1 to4 carbon atoms such as methyl, ethyl, n-propyl or n-butyl groups and thelike. The preferred compounds have alkyl groups each having one or twocarbon atoms. These alkyl groups are attached to the nitrogen atom via aprimary covalent bond and thus form a dialkylamino radical which ispreferably attached to the benzene ring in the para position withrespect to the halocarbonyl group. The halogen atom of the halocarbonylgroup may be chlorine, bromine, flourine or iodine. the chloroderivative is preferred-due to its ease of handling, accessibility andreactivity.

Polyethylenimine is a commercially available material which is producedby the catalytic reaction of the cyclic compound, ethylenimine. Althoughthe monomeric material, ethylenimine, is highly toxic, polyethyleniminehas been found to be nontoxic to humans. This material is produced in awide range of molecular weights ranging from about 500 to about 100,000average molecular weight. The exact polyethylenimineused as theprecursor for the substantive sunscreen material described herein may beany of the commercially available products. Lower molecular weight(about 500 to about 2,500) materials, available in anhydrous form, areparticularly useful due to ease of handling when reacting with benzoylhalides.

The reaction product of polyethylenimine and a para-dialkylaminobenzoylhalide forms a polymeric material which may be described as polytparapolymeric dialkylaminobenzoyl)ethylenimine. The product may be formed inany conventional manner in which halocarbonyls are reacted with primaryand secondary amines. The hydrogen chloride byproduct which is formedmay be neutralized by any known means such as by adding to the reactionmixture a compound such as sodium carbonate which will react in situwith the hydrogen chloride and will form products which can easily beseparated from the desired polymeric material. Alternately, compoundsmay be added to the reaction mixture after the desired product has beenformed to neutralize any hydrogen chloride byproduct entrained in themixture. This may be done by utilizing ion exchange resins or by usingalkalis such as sodium hydroxide.

The resulting polymeric material found useful herein include copolymersof polyethyleneimine containing copolymeric materials used aspoly(pdimethylaminobenzoyl)ethylenimine. poly(pdiethylaminobenzoyl)ethylenimine, poly[p-di( npropyl)aminobenzoyl]ethylenimine,poly[pondary amines of'the polymer backbone. All'of the t polymericreaction products have, whe n tested, highly selective absorbtionqualities for radiation in the ultraviolet wavelength range betweenabout 280 millimicrons to about 320 millimicrons. This range ofradiation is known to cause the onset of sunburn or crythema on humanskin. Applicant's polymeric reaction products, when applied to the skin,in any convenient form protects the skin from these harmful radiationsby forming a substantive film which absorbs the undesirable radiation.

The amount of para-dialkyl aminobenzoyl halide which is allowed to reactwith the polymeric backbone material may be of such quantity as to causethe polymeric product formed to have from about 5 to about 80 weight percent dialkylaminobenzoyl radical pendant groups based on the totalweight of the polymeric reaction product. Higher percentages of thesependant groups may be used although are not normally necessaryto form aneffective material. The exact percent of these pendant groups which maybe incorporated onto the polymeric backbone is only limited by theamount of amino groups located thereon and the type of formulation ontowhich these products are to be used. It is realized thatv the radicalscontaining the higher alkyl groups will naturally be less in number forthe same weight percentage. Therefore, higher weight percentages ofthese radicals will be needed to produce the same protection as radicalscontaining lower alkyl groups such as the dimethylaminobenzoyl radical.

Polyethylenimine may be reacted with one or more than one specie ofdialkylaminobenzoyl halide either simultaneously or successively therebyforming a polymer reaction product having one specie of pendant group orhaving a mixture of dialkylaminobenzoyl groups.

Applicants polymeric reaction product containing the selectiveultraviolet absorption groups have been found to be highly effectivesunscreening agents in that they selectively absorb the harmful erythemaproducing rays while transmitting the more desirable tanning rays to theskin. These polymeric products readily form a film when applied to theskin which adheres thereto and is resistant to removal from the skin bythe action of fresh water, perspiration, or salt water and, therefore,is more durable under conditions which are most commonly found at thesea shore or the'poolside. The polyethylenimine substrate which acts asa binder to the keratin surface of the skin and allows theparadialkylbenzoyl pendant groups to impart sunscreening activity islonglasting and need not be applied periodically by the individual aftereach contact with the water nor periodically due to the action of bodyperspiration. The polymeric sunscreening agent may have pendant groupswhich are all the same such as the dimethylaminobenzoyl radical or,alternatively, mixtures of dialkylaminobenzoyl halides may be reactedwith polyethylenimine to form a mixed dialkylaminobenzoylpolyethylenimine polymeric material.

The polymeric material containing from about 5 to about 80 weight percent pendant groups on the polymeric backbone may be combined withadditional materials to form a sunscreening composition. Thesecompositions may contain from 1 percent to about 50 percent of thepolymeric reaction product based on the weight of the total composition.Compositions containing from 1 percent to 25 percent of the polymer havebeen found satisfactory under normal conditions. The exact amount ofpolymeric product incorporated in the sunscreening compositions hereindisclosed will depend uponthe exact amount of pendant groups in thepolymeric backbone and the degree of protection which is desired in aparticular preparation. The form ulator of any particular preparationmay calculate the percent of reactive sunscreening groups whichis'ultimately in any preparation by knowing the percentage of pendantgroups in the polyethylenimine polymer re- 7 action product. The amountof pendant groups which affords ample protection is from about 0.1 to 10percent of the tot'al'formulation. For example, protection can beattained by forming a sunscreening composition containing 1.0 percentdimethylaminobenzoyl radicals.

A vehicle material is combined with the polymeric reaction productsdisclosed hereinabove to form sunscreening compositions which can bereadily dispensed onto the skin of the user. These materials may be awater-alcohol mixture, water and oil cream or an oil base, ascustomarily known to those skilled in the art. The water-alcohol basemay contain up to percent of an alcohol material having lower alkylgroups such as methanol, ethanol, propanol and the like. Alternately, orin combination, the water-alcohol vehicle material may contain dihydroxyalcohols such as ethylene glycol, propylene glycol and the like. The oilbase or the oil and water cream materials may contain oils which arecommonly used and are known to those skilled in the art. Examples ofsuch oils are mineral, vegetable and animal oils. Emulsions of thesunscreening polymeric reaction product may be made with any of thesebase materials to form a homoge'nous mixture which can be subsequentlyapplied to the skin.

' The compositions herein disclosed may, in addition, contain theusual'quantities of additional ingredients. These ingredients includeemulsifiers, fillers, perfumes, stabilizers, and the like commonly usedin such preparations.

The compositions thus formed can be easily applied to the skin of theuser and will readily form a film'material which contains theerythema-protecting polymeric agent. In the case of a water-alcoholbased material the volatile base will evaporate and leave on the skin acontinuous transparent film material. Such films will provide completeand long lasting protection against erythema-producing rays' and it hasbeen found that these films are not easily removed by the action offresh or salt water or through the perspiration of the user. The

oil base materials and the water and oil base compositions will form acontinuous oily film of the desired polymeric sunscreening material.These films also provide complete and'long lasting protection againstsun induced erythema. Sunscreening compositions are generally used inhot weather and at beaches where people enjoy bathing activities. It istherefore, essential that the protective coating applied to the skin isnot appreciably effected by water or perspiration. The compositionsherein disclosed form a thin layer of protective coating on the skin ofthe user and will form a long lasting material which is not easilyremoved by the action of fresh or salt water or through perspiration.Therefore, the compositions disclosed herein offer a more complete andefficient protection than compositions known and commonly sold on themarket.

The following examples herein disclosed are for illustrative purposesonly and are not meant to be limiting upon the invention concept exceptas set forth in the appended claims. All parts and percentages are byweight unless otherwise indicated.

EXAMPLE I polytp-dimethylaminobenzoyl)ethylenimine l0 parts mineral oil(U.S.P.) 45 parts peanut oil 45 parts The oily lotion is applied to theskin of a user. The film formed offered complete protection tosunburning even after several hours of bathing and being'in the sun.

EXAMPLE u A composition was prepared of the dimethylaminobenzoylchloride and polyethylenimine reaction product as described in Example Iwhich is incorporated into an aqueous alcoholic solution. A typicalexample of such a composition is as follows:

parts poly(p-dimethylaminobenzoyl)ethylenimine ethyl alcohol parts water50 parts Such a composition is applied to the skin and when the volatilevehicles evaporate sunscreening polymeric material forms a continuousfilm on the skin of the user and is found to be resistant to water andperspiration and, therefore, forms an effective longlasting protectionto erythema-causing rays.

EXAMPLE Ill A polymeric reaction product was prepared by reactingdiethylaminobenzoyl chloride with polyethylenimine of 1,800 averagemolecular weight. The resultant product contained 20 percent by weight,based on the total weight of the polymeric material, of thediethylaminobenzoyl radical as determined by an oxygen analysis of theproduct. The product is incorporated into a cosmetic lotion to form anemulsion and is applied to the skin to produce a continuous film of thepolymeric product upon evaporation of the more volatile vehicles. Thisfilm is durable to water and perspiration and was found to givelonglasting protection to erythema causing rays.

it will be understood that it is intended to cover all changes andmodifications of the examples of the invention herein chosen for thepurpose of illustration which do not constitute departures from thespirit and scope of the invention.

A What is claimed is:

1. A method of protecting the human skin from erythema inducingultraviolet radiation which comprises applying to the skin a compositioncontaining from 1 percent to about 75 percent based on the totalweightof the composition of a polymeric reaction product of at least onep-di-C -C -alkylaminobenzoyl halide with polyethylenimine having anaverage molecular weight ranging from about 500 to 100,000 in a topicalskin cosmetic carrier material selectedfrom the group consisting ofwater-lower alcohol mixture, and an aminal, vegetable and mineral oilbase.

2. A method according to claim 1 wherein the p dialkylaminobenzoylhalide is p-dimethylaminobenzoyl chloride. v p

3. A method according to claim 1 wherein the carrier material is alotion.

4. A method according to claim 1' wherein the polymeric reaction productcontains from 5 to 80 weight percent based on the total weight of thepolymeric material of the residue group of p-dialkylaminobenzoyl halide.

5. A method according to claim 1 wherein the carrier material is awater-lower alkyl alcohol mixture having up to percent by weightalcohol.

6. A substantive polymeric sunscreening composition comprising apolymeric reaction product of a polyethylenimine and a di-C -C-alkylaminobenzoyl halide having an average molecular weight of fromabout 500 to 100,000, wherein said product contains thedialkylaminobenzoyl groups pendant to the polymeric backbone and atopical skin cosmetic carrier material selected from the groupconsisting of water-lower alcohol mixture, and an animal, vegetable ormineral oil base.

7. A composition of claim 6 wherein the pendant dialkylaminobenzoylgroups are in a concentration ranging from about 0.1 percent to about10.0 percent based on the total weight of the composition.

8. A composition of claim 6 wherein the dialkylaminobenzoyl halide isdimethylaminobenzoyl chloride.

9. A composition according to claim 6 wherein the cosmetic carrier is awater-lower alkyl alcohol mixture

1. A METHOD OF PROTECTING THE HUMAN SKIN FROM ERYTHEMA INDUCINGULTRAVOILET RADIATION WHICH COMPRISES APPLYING TO THE SKIN A COMPOSITIONCONTAINING FROM 1 PERCENT TO ABOUT 75 PERCENT BASED ON THE TOTAL WEIGHTOF THE COMPOSITION OF A POLYMERIC REACTION PRODUCT OF AT LEAST ONEPI-DI-C1-C4ALKYLAMINOBENZOYL HALIDE WITH POLYETHYLENIMINE HAVING ANAVERAGE MOLECULAR WEIGHT RANGING FROM ABOUT 500 TO 100,000 IN A TOPICALSKIN COSMETIC CARRIER MATERIAL SELECTED FROM THE GROUP CONSISTING OFWATER-LOWER ALCOHOL MIXTURE, AND AN AMINAL, VEGETABLE AND MINERAL OILBASE.
 2. A method according to claim 1 wherein the p-dialkylaminobenzoylhalide is p-dimethylaminobenzoyl chloride.
 3. A method according toclaim 1 wherein the carrier material is a lotion.
 4. A method accordingto claim 1 wherein the polymeric reaction product contains from 5 to 80weight percent based on the total weight of the polymeric material ofthe residue group of p-dialkylaminobenzoyl halide.
 5. A method accordingto claim 1 wherein the carrier material is a water-lower alkyl alcoholmixture having up to 75 percent by weight alcohol.
 6. A substantivepolymeric sunscreening composition comprising a polymeric reactionproduct of a polyethylenimine and a di-C1-C4-alkylaminobenzoyl halidehaving an average molecular weight of from about 500 to 100,000, whereinsaid product contains the dialkylaminobeNzoyl groups pendant to thepolymeric backbone and a topical skin cosmetic carrier material selectedfrom the group consisting of water-lower alcohol mixture, and an animal,vegetable or mineral oil base.
 7. A composition of claim 6 wherein thependant dialkylaminobenzoyl groups are in a concentration ranging fromabout 0.1 percent to about 10.0 percent based on the total weight of thecomposition.
 8. A composition of claim 6 wherein the dialkylaminobenzoylhalide is dimethylaminobenzoyl chloride.
 9. A composition according toclaim 6 wherein the cosmetic carrier is a water-lower alkyl alcoholmixture having up to 75 percent by weight alcohol.